Process and device for reducing sheet metal



Feb. 28, 1939. E B HUDSON I 2,148,469

PROCESS AND DEVICE FOR REDUCING SHEET METAL Filed July 6, 1936 8Sheets-Sheet 1 INVENTOR. [aw/1v J5. Hausa/v,

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ATTORN EYS Feb. 28, 1939.

E. B. HUDSON- PROCESS AND DEVICE FOR REDUCING sHEET METAL Filed July 6,1956 8 Sheets-Sheet INVENTOR v 151 #005 ON,

F/GEZ Feb. 28, 1939. E, B HUDSON 2,148,469

PROCESS AND DEVICE FOR REDUCTNG SHEET METAL Filed July 6, 1956 8Sheets-Sheet 3 1 5 7 U 4 NW '3] ATTO RN EYJ.

Feb. 28, 1939. i E, B HUDSON v 2,148,469

PROCESS AND DEVTCE FOR REDUCTNG SHEET METAL Filed July 6, 1936 8Sheets-Sheet 4 4 INVENTOR BY alwrd ATTORNEYS Feb.

28, 1939. E. a HUDSON PROCESS AND DEVICE FOR REDUCTNG SHEET METAL FiledJuly 6, 1936 8 Sheets$heet 5 INVENTOR DWI/V .5. Hanson.

BY flaqll ATTORNEYS,

Feb. 28, 1939.

E. B. HUDSON 2,148,469

PROCESS AND DEVICE FOR REDUCING SHEET METAL Filed July 6, 1936 8Sheets-Sheet 6 un-I INVENTOR Elmo/v .B. flaaso/v.

ATTORNEYS,

BY M4442 Feb. 28, 1939. E. B. HUDSON PROCESS AND DEVICE FOR REDUCTNQSHEET METAL Filed July 6, 1936 8 Sheets-Sheet 7 FIG. /0.

INVENTOR Elm 11v B. fluaso/v.

BY M46 44 ATTORNEYS,

Feb. 28, 1939. E. B. HUDSON PROCESS AND DEVICE FOR REDUCTNG SHEET METALFiled July 6, 1956 8 Sheets-Sheet INVENTOR v Earw/v B huosolv.

[245 01 fi ilzw ATTORNEYS.

Patented Feb. 28, 1939 UNITED STATES PATENT OFFICE PROCESS AND DEVICEFOR REDUCING SHEET M'ETAL 14 Claims. (Cl. 205-25) My invention relatesto a new process and apparatus for reducing sheet metal in gauge; andthe several objects and advantages of my invention will be set forthhereinafter or will be clear to one skilled in the art from thedescription which follows.

Essentially, in the practice of my invention, I depart from conventionalmethods, such as rolling, for reducing metal of sheet width, and followa drawing practice in which the metal is pulled under tension betweenreducing dies. By sheet metal I mean to include rolling piecessubstantially unlimited as to gauge but characterized by the fact thatthe width of the pieces is very many times the thickness thereof. Myprocess and apparatus is particularly useful both in giving to heavysheet materials accurate sizing and transverse shape or contour, andalso in reducing finer materials to thin gauges very accurately. As aconsequence, I do not desire the term sheet materialsto be construed aslimiting my claims otherwise than to materials in which the width is somuch greater than the thickness that reduction in gauge of suchmaterials is taken up substantially entirely in elongation thereof.

It will be understood, of course, that my process is not applicable tomaterials heated to the degree which is proper for hot rolling, but isessentially a cold reduction process, since it is a process involvingthe exertion of tension to cause the piece to pass through the reducingand/or sizing dies.

The problems connected with sizing materials of sheet width by a drawingprocess are quite difierent from the problems met with in the drawing ofwire or rod. With materials which are substantially as thick as they arebroad and in which both of these dimensions are relatively small, noproblem of current control of die shape is involved. In using a long diemember on each side of the piece, the stresses set up are such as tospring the reducing members in a way that is quite analogous to thespringing of the rolls in cold rolling processes. As a consequence, thecontrol of die shape becomes very vital, and a part of my invention isconcerned with the maintenance of accurate die contour under theconditions.

My invention is especially well adapted for reduring metals to the gagesthinner than 20 gage. When the conventional mill is used in this rangeof reduction great cost is experienced in maintaining bearings and millrolls. In the manufacture of wire, the rolling of wire rod stops at No.gage (.22) and the rod is then further reduced by drawing, which is themost practicable method. I propose in accordance with my invention, thatmetal strip be rolled to .040 thick, and then further reduced bydrawing. Thus I reduce the cost of manufacture and give more accurategage than is possible by rolling.

The various objects of my invention are accomplished in that process andby the use of that arrangement and organization of mechanism of which Ishall now describe an exemplary embodiment.

Reference is now had to the drawings, wherein:-

Figure 1 shows the mill in plan complete with devices and coiling reels.

Figure 2 shows the mill in elevation on the operating side.

Figure 3 shows the mill in section along the center line of the work.

Figure 4 shows the mill in elevation front view.

Figure 5 shows an enlarged sectional view of the die block and die beamtogether with induction coil and cooling pipes.

Figure 6 shows the die beam of the induction heated type in plan.

Figure 7 same as Figure 6 except in elevation.

Figure 8 shows deflection indicating device (Patent 1,928,457)

Figure 9 shows another type of die beam heated by a resistance coil.

Figure 10 shows section I-I of Figure 9.

Figure 11 shows wiring diagram of deflection indicating and controllingmeans of the induction circuit for heating the die beam and means forcontrolling the flow of cooling water.

The exemplary embodiment of my mechanism which I shall now describe isone employing a framework analogous to the framework of known coldrolling mills. Indeed it is possible to adapt to present mills the novelmechanism which I shall describe. Thus I have shown in Figures 1.

. 2, 3, and 4 a mill comprising interspaced housings l, of ordinaryform. Instead of journaling rolls in these housings, however, I slidablymount a pair of beams therein, designated respectively at 5 and 5. Themill housings, of course, rest upon suitable supporting members 2, on afoundation 3. The housings may be held apart at the top by a suitablebridge indicated at 4. The beams 5 and 5' bear reducing dies and 20" Iwhich will be more particularly described here- I have disclosed arelatively simple form of motor driven screw down, in which wedges "Iare introduced between the upper portions of the mill housings and theportions of the beam 5 which enter the slots in the housings. Actuallythe wedges I may contact a bearing and rocker block 6 resting on the endof the beam 5. The wedges are moved in and out in opposite directionsbymeans of shafts 2| threaded therein and driven by a motor 22 throughtwo sets of suitable planetary or other gear reductions 23 and 24. The

motor and the gearing may be mounted, as shown,

on the bridge 4'. If it is desired to raise or lower one end of the beam5 more than the other end,

- it will be competent to attach a separate motor toone of the shafts 2|and provide a suitable clutch mechanismbetween this shaft and itsappropriate gearing. It is likewise possible to employa separate motorfor each of the shafts 2|, or to use a single motor and provide clutchesbetween it and the two shafts 2|, so that either or both of them can bedriven. All of this is within the skill of the worker in the art toprovide, to-

gether with the necessary controls therefor. Since I have shown a wedgescrew down, I have shown also means for pulling up the beam 5 of beams 5and 5' inmymillinstead ofrolls or a series of rolls, narrower millhousings may be employed and considerable space and expense saved,because it is not necessary to provide space in the housings for rollneck bearings and the like. Moreover, since the beams 5 and 5' are ofrelatively great depth, my mill is very much more rigid than a rollingmill would be.

As I have indicated, the die members 20 and 20 are connected to thelower and upper faces of the'beams 5 and 5' respectively. These diemembers are attached in any suitable way and are preferably keyed, asshown, to the beams to resist transverse displacement. They are providedwith die faces Ill and I forming a constricted die throat through whichthe metal is drawn. They are made removable, as indicated, forreplacement, and they are the only parts of my mill structure subject toheavy wear. Where the mill is, as shown, a reversible mill, the diefaces I0 and 0' are so shaped as to permit drawing in either direction.I have shown in connection with my mill two tight coilers 25 and 26 towhich the ends of a strip to be rolled may be attached, and which areprovided withsuitable drives comprising motors 25a and 26a and gearing25b and 2617., They will also be provided with alternatively actingbrake means and with clutch means as at 260 (Figure 4). The strip isindicated at 21 and it passes from one coiler to the other over kneerolls 28 and 29 between the die faces l0 and Ill. The die members arepreferably drilled as at 30, and provided with jetopenings' 3| so thaton both sides a spray or bath of lubricant can be projected against thepiece as it enters the die, for cooling and lubricating.

In spiteof thegreat vertical thickness of the beams and 5', there isbound to be a normal deflection thereof under the stresses of reduction,which deflection will vary the contour of the die throat. Consideringthe upper beam 5,

when metal is being drawn through the die throat, this beam will be veryheavily loaded from beneath. beam contracts and the upper edge of thebeam expands. I do not attempt to correct this deflection by externalpressures applied to the beams. On the contrary, I have found that adeflected beam may be brought back to an undeflected position either byheating the contracted edge of it, or cooling the expanded edge of it,making use of the contraction and expansion of the metal forming thebeam under conditions of temperature variation. It will be clear that ifcooling and heating means are both employed, these need be applied tobut one edge of the beam to secure the same effect." Any heating andcooling means may be employed. The

to employ a fluid cooling medium and pass it through a series ofperforations i=3 in the lower end ofthe beam 5, as shown. Theseperforations may be connected in series or multiple, or portions inseries and portions .in multiple, and a cooling fluid sent therethroughby mwns of a pump or some other pressure means.

- Where it is possible to control the temperature of the fluid meansreferred to and to vary that temperature rapidly, it will be possible touse the 30 fluid means both for heating and for cooling, as will bereadily understood. However, the variation of the temperature of a fluidmeans rapidly and accurately involves some problems, and I find itpreferable to use the fluid means as a cooling medium and to apply tothe beam some other direct or indirect acting heating means. Thus, theheating may also be done by fluid or it may be done by'electricalresistance, or it may be done by electrical induction. In my drawings,40

Fig. 3, I have shown at M an inductive winding about the lower end ofthe beam embedded in a suitable insulative material l2 and covered by aface plate 32. This winding may be energized by alternating current ofrelatively high frequency Moreover, the heating and cooling means may,55

if desired, be applied locally to different portions of the beams so asto permit the production of special contours. This, however, is notordinarily necessary or desirable, the general object be ing to maintainthe die throat of constant width throughout its length, in spite ofvariations of load, temperature, and the like.

In Figures 9 and 10, I have shown the beam 5 equipped not only with thecooling passageways l3 in its lower portion, for the flow of a coolingfluid as hereinabove described, but also with electrical resistanceheating means. These means comprise resistance heaters indicated at 40contained within bores 4| in the beam 5. It will be understood that theresistance wires are either sheathed with insulative substance, or thatthe bores 4| are lined wlth insulative substance. As shown, it isdesirable to increase the eflective length of the resistance wire nearthe center of the'beam so as to increase the heating effect Indeflecting, the lower edge of the 5 most feasible cooling procedureknown to me is 20 there. This can be accomplished by winding the turnsof resistance wire closer together on a suitable core near the center ofthe beam, or in other ways known to the art. Suitable electricalconnections are of course provided as at 42.

The mid section of the beam may be reduced as shown. Where the heatingand cooling are efiective essentially at one edge of the beam, it iswell to provide means inhibiting heat transfer from one edge of the beamto the other. To this end, I have shown cooling means A, comprisingchambers through which a cooling fluid may continuously be circulated,located at the reduced portion of the beam and adjacent that edge whichis not provided with contour controlling means. These means can be seenin Figures 2, 3, '7, 8, 9 and 10.

Inasmuch as the contour of the die throat tends to vary with thesevariables, it is advisable to provide automatic means for controllingthe die throat contour by varying the heating and cooling media which Ihave described. The measurements effecting the automatic control may bederived from various sources, including calipering of the piece beingrolled; but I have found it most convenient automatically to control thecontour by means of a measurement of the deflection of the beam. To thisend I employ a deflection gauge comprising a rigid arm 15 (see Figures6, 7, and 8) mounted near one end of the beam on a block 45 and bearingat its other end an adjustable actuating means 43. This operates acontrolling device 14 mounted on a bracket 44 mounted on a block 46 nearthe other end of the beam.

The type of controlling device which I prefer to use is a deviceindicated diagrammatically in Figure 11, and is an adaptation of gaugingmeans shown in the patent to Mershon et al., No. 1,928,457, issued Sept.26, 1933. It operates on the principle of unbalance due to changes inthe magnetic reluctance of one or more arms in a Wheatstone bridge. Theactuating means hitherto described includes a member of magneticmaterial 41 adapted to be moved upon changes in the deflection of beam,with relation to two magnetic coils 48 and 49. These two coils form twoof the arms of a Wheatstone bridge and the other two arms are formed ofequal and opposed windings, 5B and 5| on a core 52. Current is suppliedacross one diagonal of the bridge from the secondary 53 of a transformer54 the primary 55 of which may be connected through a suitable switchand fuses, panel 56 to power leads 51. As an alternative of course amotor generator may be used. The Wheatstone bridge is energized byalternating current of a frequency such as to be outside any naturalvibrating frequency of the member 47.

Across the other diagonal of the Wheatstone bridge there may beconnected a meter B on which the deflection can be read and a sensitiverelay G, through a rectifier 58.

In operation the movement of the member 41 varies the magneticreluctanceof the coils 48 and 49 thereby unbalancing the bridge. Thisgives an appropriate leading on the motor B and a controlling movementof the relay G. The motor as shown in Figure 2 may be mounted on themill housing in a position of convenience to the mill operator.

The relay G may be caused through an appropriate circuit to operate asolenoid valve for control of the cooling fluid in the passageways 13.This valve is diagrammatically indicated at H.

It may be caused alternatively by an appropriate circuit to actuate asolenoid switch I for control of the heating medium the relay andsolenoid circuits may have a direct current supply through leads 59.

I have shown in this figure also a heating means controlled by thesolenoid switch I and comprising a motor E deriving its current frompower leads 60 while this motor is coupled to a high-frequency generatorF the output of which is passed through suitable leads to the highfrequency inductive heating coils l I. It will be clear that the switchI may be used to control any other type of heating means.

It will be understood that the construction of the lower beam 5 is acounterpart of the construction of the upper beam 5 inasmuch as contourcontrol from both sides is necessary, and that like control, and heatingand cooling means are provided for the beam '5'.

A mill of this character is, as compared with other mills, relativelyinexpensive to build and it is of great utility in the reduction ofsizing of metal pieces with extreme degrees of accuracy. Considerablereductions can also be efiected as will be understood, dependingsomewhat upon the kind and character of metal being treated. Wide, thinsheet metal can be produced in a mill of this type without substantialvariations in gauge across the width thereof. The mill is economical inoperation because, as has been indicated, the die members are the onlyparts subject to'great wear and the only parts which have to be renewedduring the life of the machine. The mill is not a driven mill, the powerbeing applied to the piece to draw it through the die. Thus when themill of Fig. 1 is operating in the direction of the arrow, power will beapplied to the tight coiler 26 by braking means, or a lesser degree ofpower may be also applied to the coiler 25 so as to extert a backtension on the piece. Means for the maintenance of tension to a constantvalue in spite. of sporadic variations in elongation may likewise beemployed as set forth in my copending applications, Serial No. 31,346,filed July 15, 1935, and Serial No. 668,101, filed Apr. 26, 1933.

It will be clear that in the following of my process different apparatusmay be employed; and modifications may be made in my invention withoutdeparting from the spirit thereof.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. A process of sizing or reducing metal of sheet width which comprisesdrawing it under tension between interspaced die elements forming a longnarrow constricted throat, backing up said die elements by means ofsubstantially rigid, non-rotative beam members and varying the distancebetween said beam members to control the amount of reduction, whilevarying the contour of said beam members to control the contour of thereduced piece.

2. A process of sizing or reducing metal of sheet width which comprisesdrawing it under tension between interspaced die elements forming a longnarrow constricted throat, backing up said die elements by means ofsubstantially rigid, non-rotative beam members and varying the distancebetween said beam members to control the amount of reduction, andcompensating for deflection of said beam members by controlling thetemperature of parts thereof, selectively.

3. A process of sizing or reducing metal of sheet width which comprisesdrawingit under tension between interspaced die elements forming a longnarrow constricted throat as set forth in claim 2, and continuouslyflowing on said metal as it enters between said die elements, a bath oflubricating material.

4. A method of contour control in mills which comprises providingsubstantially rigid, non-rotative beams for resisting the outward forcesof metal being reduced, and compensating for deflection of said beams byselectively controlling the expansion and contraction of portionsthereof which are interspaced relative to each other substantially inthe plane of said deflection.

5. A method of contour control in mills which comprises providingsubstantially rigid, non-rotative beams for resisting the outward forcesof metal being reduced, and compensating for deflection of said beams byselectively controlling the expansion and contraction of portionsthereof which are interspaced relative to each other substantially inthe plane of said deflection, by controlling the relative temperaturesof said inspaced portions.

6. In a sheet metal reduction mill, housing means, a pair ofsubstantially rigid, non-rotative beams, die members attached to saidbeams, means for moving at least one of said beams relative to theother, and means for varying the contour of said beams.

7. In a sheet metal reduction mill, housing means, a pair ofsubstantially rigid, non-rotative beams, die members attached to saidbeams, means for moving at least one of said beams relative to theother, and means for compensating for deflection of said beams byheating and cooling at least one edge of each.

8. In a sheet metal reduction mill, housing means, a pair ofsubstantially rigid, non-rotative beams, die members attached to saidbeams, means for moving at least one of said beams relative to theother, and means for compensating for deflection of said beams byheating and cooling at least one edge of each, said means comprisingmeans for passing a fluidin heat exchange relationship to said edge.

9. In a sheet metal reduction mill, housing means, a pair ofsubstantially rigid beams, die members attached to said beams, means formoving at least one of said beams relative to the other, means forcompensating for deflection of said beams by heating and cooling atleast one edge of each, said means comprising means for passing a fluidin heat exchange relationship to said edge, and means for electricallyheating said edge.

10. In a sheet metal reduction mill, housing means, a pair ofsubstantially rigid, non-rotative beams, die members attached to saidbeams, means for moving at least one of said beams relative to eachother, and means for compensat ing for the deflection of said beams,said means comprising passageways in adjacent edges of said beams for acooling medium, and means for applying an expansible force electricallyto said edges of said beams.

11. In combination in a mill, housings, substantially rigid,non-rotative beams extending across said housings, one of which at leastis slidably mounted therein, screw down means for efiecting the movementof said slidably mounted beam in said housings, pull back means foreffecting movement thereof in the opposite direction, and means forcontrolling the deflection of said beams under load, said meanscomprising 'means for heating and cooling an edge portion of each ofsaid beams.

12. In combination in a mill, housings, substantially rigid beamsextending. across said housings, one of which at least is slidablymounted therein, screw down means for effecting the movement of saidslidably mounted beam in said housings, pull back means for efiectingmovement thereof in the opposite direction, and means for controllingthe deflection of said beams under load, said means comprising means forheating and cooling an edge portion of each of said beams, means formeasuring the deflection of said beams and a connection between saidmeasuring means and said heating and cooling means to effect theautomatic maintenance of a desired contour in said beams.

13. In combination in a mill, housings, substantially rigid,non-rotative beams extending across said housings, one of which at leastis slidably mounted therein, screw down means for effecting the movementof said slidably mounted beam in said housings, pull back means foreffecting movement thereof in the opposite direction, and means forcontrolling the deflection of said beams under load, said meanscomprising means for heating and cooling an edge portion of each of saidbeams, said means comprising passageways in said beams for a coolingfluid, and means in connection with said beams for applying electricalheat thereto, inductively.

14. In a sheet metal reduction mill, housing means, a pair ofsubstantially rigid beams, die

' members to said beams, means for moving at least one of said beamsrelative to the other, and means for compensating for deflection of saidbeams by heating and cooling one edge of each, and means for preventingheat transfer from said edge to the opposite edge of each.

EDWIN B. HUDSON.

